Mic passthrough silently died on real hosts. Root causes, all fixed: - No liveness anywhere: a PipeWire restart (Linux) or any WASAPI device error (Windows) killed the backend worker; push() fed the dead queue for the rest of the host's life. VirtualMic now has a liveness contract (push -> bool, alive(), discard()) and the new shared audio::MicPump reopens with backoff, probing on an idle heartbeat so the mic heals BETWEEN sessions too. Validated live: systemctl restart pipewire -> node back in ~0.5 s, tone flows through the reopened backend. - Lazy creation: the mic device didn't exist until the first 0xCB frame, but games bind their capture device at launch and never re-follow. The pump opens eagerly at host start (node exists with zero clients, elected default source). - Windows headless dead-end: with VB-CABLE as the ONLY render endpoint (exactly what the installer ships), the anti-echo guard rejected the cable as the default render endpoint -> mic permanently dead. The new wiring_plan (pure, unit-tested on every platform) assigns the mic its endpoint FIRST (cable reserved for the mic), points the loopback at a DIFFERENT endpoint, and the capture side now yields (explicit endpoint or honest error) instead of the mic dying. Plan recomputed per (re)open — endpoints churn at boot/logon/driver installs. - Stale bursts: buffered audio from a previous session played into a newly-attached recorder (observed live). Timestamped chunks + a consumer-gap check in the process callback age everything past 1 s. The Linux node mechanism stays the stream-based Audio/Source with RT_PROCESS + priority.session: the canonical null-audio-sink adapter recipe was tested on this box (PipeWire 1.6.2) and never gets a clock (QUANT 0 -> pure silence), and WirePlumber reroutes a feeder targeting it to the default sink (echo). Decision documented in the module docs. Live-validated on this box (synthetic host + probe --mic-test, pw-record): eager node, both attach orderings, PipeWire-restart self-heal, post-session silence. Windows side compile/CI + on-glass validation pending. Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
punktfunk-host
The streaming host — the program you run on the machine whose desktop or games you want to stream. For each client that connects, it spins up a virtual display sized to that device, captures it on the GPU, encodes with hardware NVENC/VAAPI/AMF/QSV, and sends it out over a low-latency transport — no physical monitor, no letterboxing, no rearranging your real screens.
It speaks two protocols from one process:
- GameStream — so any Moonlight / Artemis client works day one.
punktfunk/1— punktfunk's own faster protocol (QUIC control plane, GF(2¹⁶) FEC + AES-GCM data plane) that the native clients use.
Runs on Linux (the primary, most battle-tested path) and Windows (x64). The shared protocol,
FEC, and crypto live in punktfunk-core; this crate is everything
platform-facing around it.
What it does
- Per-client virtual displays at the exact WxH@Hz. Linux uses per-compositor backends — KWin, gamescope, Mutter, and Sway/wlroots; Windows uses its own all-Rust IddCx virtual display, even on the secure desktop (UAC / lock screen).
- GPU zero-copy capture → encode. dmabuf → CUDA/Vulkan → NVENC on Linux; DXGI/WGC → GPU encode on Windows. Encoders auto-select by GPU vendor: NVENC (NVIDIA), VAAPI (Linux AMD/Intel), AMF/QSV (Windows AMD/Intel), or software H.264 as a floor. HDR/10-bit and HEVC 4:4:4 supported.
- Input injection. Mouse/keyboard (libei / gamescope EIS / wlr / Windows SendInput) and virtual gamepads — Xbox 360/One, DualSense, DualShock 4 — with rumble and HID feedback back-channels.
- Audio both ways. Opus audio host→client, plus a virtual microphone the client can talk into.
- Trust & discovery. A persistent host identity, SPAKE2 PIN pairing (default) or TOFU, and mDNS auto-advertisement so clients find the host without typing an IP.
- Management API + web console. A REST API (
mgmt.rs, OpenAPI atapi/openapi.json) drives status, paired devices, and on-demand pairing; the browser UI is inweb/.
Run it
punktfunk-host serve runs inside your desktop session. Bare serve is the secure native-only
default (punktfunk/1 + the management API); add --gamestream on a trusted LAN to also accept
stock Moonlight clients.
# Linux, from the repo root (see the repo README "Running on this box" for the headless recipe):
cargo run -rp punktfunk-host -- serve # native-only (secure default)
cargo run -rp punktfunk-host -- serve --gamestream # + Moonlight compatibility
Then pair from the web console (https://<host-ip>:47992) or the client app.
Most people should install a package rather than run from source — see
packaging/ (apt · rpm/COPR/bootc · Arch/sysext · Windows installer) and
the per-platform guides at docs.punktfunk.unom.io/docs/install.
Subcommands
| Command | Purpose |
|---|---|
serve |
The host (native punktfunk/1 + mgmt API; --gamestream adds Moonlight). |
punktfunk1-host |
Standalone native-protocol listener for testing/measurement (--source virtual, --max-sessions). |
openapi |
Print the management-API OpenAPI spec (regenerates api/openapi.json). |
library |
Inspect the multi-store game library. |
service · driver · web |
Windows: SCM service, driver install, bundled web console. |
*-test / *-selftest / *-probe |
Diagnostics (input, zero-copy, HDR, compositor, gamepads). |
--help lists them all.
Layout
src/
main.rs CLI + subcommand dispatch
config.rs · session_plan.rs · session_tuning.rs · pipeline.rs session setup + the frame pipeline
vdisplay/ per-compositor virtual outputs (kwin · gamescope · mutter · wlroots)
capture/ · capture.rs screen/dmabuf capture (+ Windows DXGI/WGC)
encode/ · encode.rs per-GPU encoders (nvenc · vaapi · ffmpeg_win (AMF/QSV) · sw)
zerocopy/ dmabuf → CUDA → NVENC bridges (EGL/GL tiled, Vulkan LINEAR)
inject/ · inject.rs input backends (libei · wlr · uinput gamepads · UHID DualSense/DS4)
audio/ · audio.rs Opus out + virtual mic (PipeWire / WASAPI)
gamestream/ Moonlight compat: nvhttp · pairing · rtsp · control · stream · gamepad · apps
punktfunk1.rs the native punktfunk/1 host (QUIC control + native-thread UDP data plane)
mgmt.rs · native_pairing.rs · stats_recorder.rs management API, pairing, perf capture
hdr.rs · library.rs HDR metadata; multi-store game library
linux/ · windows/ platform-confined backends
Related
punktfunk-core— the shared protocol · FEC · crypto core- Clients — the apps that connect (Apple · Linux · Windows · Android · probe)
- Packaging & docs — install & operate
design/— architecture rationale and deep-dive plans